Field
Aspects of the present invention generally relate to a wireless power transmission technique.
Description of the Related Art
Conventionally, a wireless power transmission system is known which includes a power transmission apparatus that wirelessly transmits power and a power reception apparatus that receives power supplied from the power transmission apparatus. There are some wireless power transmission systems in which the power transmission apparatus stops transmission of power when detecting full charge of the power reception apparatus to which the power transmission apparatus transmits power.
Japanese Patent Application Laid-Open No. 2010-34080 describes that a power reception apparatus transmits a command indicating that the power reception apparatus is fully charged to a power transmission apparatus when the power reception apparatus reaches a fully charged state that is a state in which electric energy is fully stored in a storage battery or a capacitor. Japanese Patent Application Laid-Open No. 2010-34080 further describes a technique in which the power transmission apparatus stops the transmission of power to the power reception apparatus when the power transmission apparatus receives a command indicating that the power reception apparatus is fully charged from the power reception apparatus.
In the wireless power transmission system as described above, prior to the wireless power transmission, it is necessary to perform authentication processing between the power transmission apparatus and the power reception apparatus to confirm whether wireless power transmission methods used by the power transmission apparatus and the power reception apparatus correspond to each other.
However, if the power reception apparatus is still placed on the power transmission apparatus, which is a power transmissible range, even after the power reception apparatus is fully charged, the power transmission apparatus may start authentication processing again with the power reception apparatus that is fully charged.
For example, while the power transmission apparatus is transmitting power to the power reception apparatus, the power reception apparatus transmits a command for requesting stopping of the power transmission to the power transmission apparatus because the power reception apparatus is fully charged. The power transmission apparatus responds to receipt of the command for requesting stopping of the power transmission and stops the transmission of the power to the power reception apparatus. However, if the power reception apparatus is still placed in a power transmission range of the power transmission apparatus, the power transmission apparatus detects the power reception apparatus, so that the authentication processing is started again. In this case, for example, the power transmission apparatus receives a command indicating that the power transmission is unnecessary from the power reception apparatus during the authentication processing, so that the power transmission apparatus does not perform the wireless power transmission on the power reception apparatus. In this way, the power transmission apparatus may perform processing for unnecessary power transmission such as useless communication on the power reception apparatus to which the power transmission apparatus has already transmitted power and which is fully charged and does not need power transmission.